Filter for diesel engine fuel

ABSTRACT

A filter for Diesel engine fuel, comprising a filtering mass which is contained within an enclosure and is provided so as to be crossed by the fuel in its path inside the filter between an intake connector and a discharge connector. The enclosure comprises a water collection chamber at its bottom. The filter further comprises at least two micromeshes which are adapted to be crossed sequentially by the fuel that exits from the filtering mass.

TECHNICAL FIELD

[0001] The present invention relates to a filter for Diesel engine fuel.

BACKGROUND ART

[0002] It is known that filters inserted in the supply circuit of Dieselengine fuel, commonly known as Diesel fuel, comprise means adapted toseparate the water contained in the fuel, but these means are less thanfully satisfactory.

[0003] A very common type of filter utilizes the phenomenon ofcoalescence, according to which the microscopic water droplets that passthrough the filtering mass mixed in with the Diesel fuel tend to mergealong the path leading to the peripheral region of the fibers of saidfiltering mass, forming drops of a certain size which appear on thesurface on which the Diesel fuel exits from said mass.

[0004] Some of these drops slide downward along said surface by gravityand collect in a chamber provided at the bottom of the filter, forming amass of water which is periodically evacuated, but many of the dropsescape from the surface, entrained by the Diesel fuel in its motion, andthus remain included therein, causing a loss of effectiveness of thefilter.

DISCLOSURE OF THE INVENTION

[0005] The aim of the present invention is to provide a filter forDiesel engine fuel which ensures high efficiency in eliminating waterfrom the fuel.

[0006] This aim is achieved by a filter for Diesel engine fuel,according to the invention, comprising a filtering mass which iscontained within an enclosure, said mass being designed to be crossed bythe fuel in its path inside the filter between an intake connector and adischarge connector, said enclosure comprising a water collectionchamber at the bottom, characterized in that it comprises at least twomicromeshes which are adapted to be crossed sequentially by the fuelthat exits from the filtering mass.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Further characteristics and advantages of the present inventionwill become better apparent from the following detailed description ofsome preferred but not exclusive embodiments thereof, illustrated onlyby way of non-limitative example in the accompanying drawings, wherein:

[0008]FIG. 1 is a partial sectional view, taken along a longitudinalplane, of the invention according to a first embodiment;

[0009]FIG. 2 is a view of a second embodiment of the invention;

[0010]FIGS. 3, 4 and 5 are views of three variations of the invention,comprising a sleeve for reinforcing the filtering mass;

[0011]FIGS. 6 and 7 are views of two further embodiments of theinvention.

WAYS OF CARRYING OUT THE INVENTION

[0012] With reference to FIG. 1, reference numeral 1 generallydesignates a filter comprising a per se known structure which is adaptedto determine, inside the enclosure 2, the circulation of the Diesel fuelindicated by the arrows in the figure between the intake connector 3located at the enclosure and the discharge connector 4 located in thecentral region, passing through the filtering mass 5.

[0013] The water droplets that have formed by coalescence during theflow of the Diesel fuel through said filtering mass emerge from thesurface 5 a of said filtering mass, and while some of the droplets, suchas 6 a, slide by gravity along the surface Sa to collect in thecollection chamber 7 provided at the bottom of the enclosure 2, theremaining droplets continue along their path, included within the Dieselfuel, and encounter the first micromesh 8 located proximate to thesurface 5 a.

[0014] Some droplets, such as 6 b, are retained at the intake of themesh, while others, such as 9 a, form at the discharge of said mesh: allthe droplets in any case slide toward the collection chamber 7.

[0015] The Diesel fuel continues in its motion, and any water dropletsthat might still be present, such as 9 b, are captured by the secondmicromesh 10 and separate from the Diesel fuel, descending into thechamber 7.

[0016] The above operating methods have been described merely as anindication, since operation is greatly influenced by the functionalparameters of the motor supplied with the treated Diesel fuel and by thedimensions of the micromeshes.

[0017] At the output of the micromesh 10, the purified Diesel fuel issent to the engine, while the water collected in the chamber 7 isemptied periodically when indicated by the sensor 11.

[0018] The micromesh 10 has a complete bottom 10 a, also made ofmicromesh, but said bottom might be only partial and provided with ablind surface, and might also be omitted.

[0019]FIG. 2 illustrates a filter 12 having the structure as describedabove and in which the first micromesh 13 is arranged so as to adhere tothe filtering mass 5, while the second micromesh 14 is located proximateto the first micromesh 13.

[0020] Some of the water droplets such as 15 a that form by coalescenceduring the flow of the fuel through the filtering mass 5 are capturedimmediately by the first micromesh 13 and slide downward along it,collecting in the collection chamber 7.

[0021] As the Diesel fuel continues in its motion, it encounters thesecond micromesh 14, and the water droplets being still present therein,such as 15 b, are captured and slide toward the chamber 7.

[0022] The micromesh 14 has a complete bottom 14 a, also made ofmicromesh, but said bottom might be only partial and provided with ablind surface, and might also be omitted.

[0023] The filters shown in FIGS. 3, 4 and 5 also have a structure asdescribed above, but they also comprise in a known manner the sleeve 16for reinforcing the filtering mass 5 which is adjacent to the internalsurface of said mass.

[0024] According to the invention, the filter 17 shown in FIG. 3 has thefirst micromesh 18 proximate to the sleeve 16 and the second micromesh19 proximate to the first micromesh 18; the filter 20 shown in FIG. 4has the first micromesh 21 in contact with the sleeve 16 and the secondmicromesh 22 proximate to the first micromesh 21; and the filter 23shown in FIG. 5 has the first micromesh 24 interposed between the sleeve16 and the filtering mass 5 and the second micromesh 25 proximate to thesleeve 16.

[0025] The description given regarding the bottoms 10 a and 14 a of themicromeshes 10 and 14 provided in the embodiments of the inventionconsidered with reference to FIGS. 1 and 2, respectively, also appliesto the bottom of the micromeshes 19, 22 and 25, designated by thereference numerals 19 a, 22 a, 25 a respectively.

[0026] Upon the above description, the functional characteristics ofthese filters are obvious and are in any case highlighted by theillustration of the water droplets shown in the respective figures;accordingly, an analytical description of said figures is deemedunnecessary.

[0027] The filter 26 shown in FIG. 6 has a structure as described above;in said filter, the first micromesh 27 comprises, at its lower end, theperforated bottom 27 a, which is connected to the second micromesh 28;variations are also possible in which said bottom 27 a is extended so asto connect to the filtering mass 5 or the bottom 28 a of the secondmicromesh has the variety of shapes mentioned earlier; the firstmicromesh might have a bottom such as 27 a even if it is located so asto adhere to the filtering mass 5.

[0028] In the filter 29 of FIG. 7, the fuel intake is provided by way ofthe connector 30 located centrally, and after passing through thefiltering mass 31 along the arrows shown in the figure, the fuel exitsfrom the filter by way of the connector 32 at the outer enclosure 33,which is provided, proximate to the bottom, with the water collectionchamber 34.

[0029] In this case, the two micromeshes 35 and 36, connected by theperforated bottom 35 a, are arranged outside the filtering mass 31; thebottom 35 a might also be omitted and the first micromesh 35 might ofcourse be arranged 30 proximate to said filtering mass 31 instead ofadhering thereto.

[0030] The described invention is susceptible of numerous othermodifications and variations, all of which are within the scope of theappended claims; thus, for example, the ends of the micromeshes can beassociated in any manner with the structure of the filter and be fixedthereto or not, and if the micromesh adheres to the supporting sleeve itcan be provided monolithically therewith; the two micromeshes mayfurther be joined in a monolithic unit.

[0031] Additional micromeshes, in addition to the two described ones,may also be provided.

[0032] The disclosures in Italian Patent Application No. MI20000A000633from which this application claims priority are incorporated herein byreference.

1. A filter for Diesel engine fuel, comprising a filtering mass (5,31)which is contained within an enclosure (2), said mass (5,31) beingdesigned to be crossed by the fuel in its path inside the filter betweenan intake connector (3,30) and a discharge connector (4,32), saidenclosure comprising a water collection chamber (7,34) at the bottom,characterized in that it comprises at least two micromeshes(8,10,13,14,18,19,21,22,24,25,27,28) which are adapted to be crossedsequentially by the fuel that exits from the filtering mass (5,31). 2.The filter according to claim 1, characterized in that it comprises afirst micromesh (8), which is adapted to be crossed by the fuel thatexits from the filtering mass (5) and is located proximate to thesurface (5 a) of said mass (5), and a second micromesh (10), which isadapted to be crossed by the fuel that exits from the first micromesh(8) and is located proximate to said first micromesh (8).
 3. The filteraccording to claim 1, characterized in that it comprises a firstmicromesh (13), which is adapted to be crossed by the fuel that exitsfrom the filtering mass (5) and adheres to said mass, and a secondmicromesh (14), which is adapted to be crossed by the fuel that exitsfrom the first micromesh (13) and is located proximate to said firstmicromesh (13).
 4. The filter according to one or more of the precedingclaims, comprising a fuel intake connector (3) which is locatedproximate to the enclosure (2), with discharge through a connector (4)located in the central region, characterized in that the secondmicromesh (10,14,19,22,25) located inside the filtering mass is at leastpartially provided with a bottom (10 a,14 a,19 a,22 a,25 a).
 5. Thefilter according to claim 4, characterized in that the bottom (10 a,14a,19 a,22 a,25 a) of the second micromesh (10,14,19,22,25) is made ofmicromesh.
 6. The filter according to claim 4, characterized in that thebottom (14 a) of the second micromesh (14) is provided with a blindsurface.
 7. The filter according to one or more of the preceding claims,comprising a fuel intake connector (3) which is located proximate to theenclosure (2), with discharge through a connector (4) located in thecentral region, characterized in that the second micromesh (10) locatedinside the filtering mass (5) is bottomless.
 8. The filter according toone or more of the preceding claims, comprising a reinforcement sleeve(16) which is adjacent to the internal surface (5 a) of the filteringmass (5), characterized in that the first micromesh (18) is locatedproximate to said sleeve (16).
 9. The filter according to one or more ofthe preceding claims, comprising a reinforcement sleeve (16) which isadjacent to the internal surface (5 a) of the filtering mass (5),characterized in that the first micromesh (21) is arranged so as toadhere to said sleeve (16) on the inner part of said sleeve (16). 10.The filter according to one or more of the preceding claims, comprisinga reinforcement sleeve (16) which is adjacent to the internal surface (5a) of the filtering mass (5), characterized in that the first micromesh(24) is interposed between the sleeve (16) and the filtering mass (5).11. The filter according to one or more of the preceding claims,characterized in that the first micromesh (27) is provided, at its lowerend, with a perforated bottom (27 a) for connection to the secondmicromesh (28).
 12. The filter according to one or more of the precedingclaims, characterized in that the first micromesh (27) located proximateto the filtering mass (5) has, at its lower end, a perforated bottom (27a) for connection to said filtering mass (5).
 13. The filter accordingto one or more of the preceding claims, characterized in that the first(18,21) and second (19,22) micromeshes are joinable in a monolithicunit.